The state of Washington has filed a complaint against Cascade Natural Gas Co. of Kennewick, alleging what staff called serious safety violations.

The staff of the Washington Utilities and Transportation Commission filed the complaint after a two-year investigation that turned up 364 alleged violations of gas safety rules. They occurred in the Tri-City area and elsewhere along the company’s 4,436 miles of natural gas pipelines in Washington.

“”We do feel strongly that our system is safe, but we have not met all requirements to document it is safe,”” said Mark Hanson, spokesman for Cascade.

The complaint filed with the commission does not request a specific penalty, but the commission can impose a fine of $100,000 for each violation of gas safety rules up to a limit of $1 million for related violations.

In the Mid-Columbia, Cascade is accused of failing to complete corrosion control monitoring for Kennewick and Walla Walla within the required 39 months.

In addition, corrosion control records were incomplete, only being kept where problems occurred and then not always including adequate information, according to the complaint.

The company did not follow its own procedures for evaluation and documentation of underground leaks, failing to document the perimeter of leaks in Richland, Kennewick and Pasco, according to the complaint. It also failed to document a follow-up to leak inspections after a leak repair at six Tri-City locations, according to the complaint.

The complaint also alleges that gas pipeline records lack sufficient details in maps or that pipelines in the Tri-Cities have not been mapped.

Elsewhere in the state, Cascade was accused of operating a pipeline at a higher pressure than allowed.

Cascade recognizes it has operation areas that need attention and is working on them, Hanson said.

Over the past 18 months, the company’s leadership has made significant investments to resolve issues, he said. That has included work to educate employees and improve documentation. It also has invested in equipment, including computerized mapping, he said.

Cascade has 20 days to file an answer to the complaint. The company has 196,000 business and residential customers in 65 communities in Washington, including Moses Lake,Walla Walla and the Tri-Cities.